In experiment, it can be realized for focusing light with a scattering lens via wavefront shaping under the current condition in laboratory nowadays, since the setting of phase modulation has been intensively investigated in theory and experiments over recent decades [1]}, [2]}, [3]}, [4]}, [5]}. However, comparing with previous works concentrating mainly on the enhanced intensity of the focused beam, we will focus on the quantum fluctuation of the focused beam.
